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Real-time monitoring of cleaner fish interactions

Tobago parrot fishCleaning is a common mutualistic relationship among tropical reef communities. The removal of ectoparasites along with diseased or damaged tissue benefits both parties; the ‘cleaner’ fish gains nutrition, whilst the ‘health’ of the client fish is maintained by parasite removal. Cleaner fish reduce parasite abundance on reef fish and have been shown to be drivers of species diversity and abundance. In the Caribbean the most common cleaner species include the Sharknose Goby (Elacatinus evelynae) a permanent cleaner, and the French Angelfish (Pomacanthus paru), a facultative cleaner. The French Angelfish only cleans whilst a juvenile, and perhaps for this reason its role in maintaining reef health has been largely overlooked. Whilst juvenile French Angelfish may not carry out significant numbers of cleaning events alone, at those stations that also have resident Sharknose cleaner gobies the two species may form a symbiotic relationship that acts to attract more clients (Hypothesis 1). If this multi-species mutualism between cleaner gobies and juvenile French angelfish attract more clients, a reduced parasite burden may be found on clients visiting these stations (Hypothesis 2), which would ultimately lead to a healthier reef. Despite a wealth of studies on cleaner fish interactions, relatively little attention has been given to the parasites of reef fish. Most studies have focused on large isopod parasites (e.g. Sikkel et al. 2004) while smaller helminth parasites have largely been ignored, particularly in the Caribbean cleaner-client system. Parasite biodiversity may be reduced in the presence of multiple cleaner species (Hypothesis 3).

Since 2010, we have collected extensive data on cleaner fish interactions on Booby Reef in the Man-O-War Bay, Tobago, identifying key Sharknose Goby and French Angelfish cleaner stations that are consistently visited more frequently than others (Fig. 1). Moreover, Cardiff University has long term data (10+ years) on the coral reef fish diversity in Tobago, and preliminary data to suggest that cleaners show repeatable behavioural traits along the Bold-Shy Continuum (Webster & Ward 2011). The proposed student will analyze these extensive data sets, use these findings as the basis for their own experiments and set up a remote-monitoring system to simultaneously record cleaner-client interactions in real-time. Training will be provided in behavioural ecology, epidemiology, social network theory and advanced statistics.


The student will join an active group of parasitologists and behaviouralists both in Cardiff and in Tobago. They will be supported by internationally recognized behaviouralists, Prof Ward and Dr Ioannou. Prof Ward currently supervisors a PhD student examining the interactions of cleaner fish in Australia and our proposed student will spend at least 3 months conducting an additional experiment in Australia, while being trained in the latest methods in fish tracking. With Dr Ioannou and his network of modellers, the student will be trained in predictive modelling and will be assisted in development of a non-invasive sensor network to remotely recognise individual animals and their interactions. The Tobago Fisheries Commission has granted all relevant permits for the capture and handling of fish, where the fieldwork will be based. Cable and Perkins have extensive experience (combined 16 years) of fieldwork in Trinidad and Tobago, and annually they teach on an undergraduate field course in Tobago.

Supervisors: Prof. Jo Cable (Cardiff), Dr. Sarah Perkins (Cardiff), Dr Christos Ioannou (Bristol), Prof. Ashley Ward (Sydney)

For information on how to apply, click here

Start date: 1 October 2015

DEADLINE for applications is 15th Jan 2015